Unsteady Cavitation Numerical Simulation Of Propeller Behind Ship Hull

With further development of the increasing velocity of ship, the rotative velocity ofpropeller is adding. In the liquid flow, when the partial pressure on the propeller reaches thesaturation vapor pressure of the liquid, the liquid appears cavity as to the vaporization.Existence of cavitation affects the hydrodynamic performance of propeller giving rise tovibration, corrosion and noise of the propeller. So prediction on the cavitation of propeller is akey to improve the hydrodynamic performance of propeller.In the present, the prediction of unsteady hydrodynamic performance of propeller ismainly based on adding the wake distribution before the propeller. Cavitation characters withthis method could be predicted well to some extent. But without considering the interactionbetween the ship and propeller, some errors in the flow field were caused. According toadequate mesh distribution and computing domain, the ship and propeller could be computedas a whole to predict the cavitation of propeller.Aiming to computing the cavitation of propeller behind ship hull, firstly, this paperstudied steady and unsteady hydrodynamic performance of propeller to get the hydrodynamiccoefficients compared with the experimental results. Secondly, steady cavitating flow over ahydrofoil and the periodic shedding phenomenon were studied. Meantime, steady cavitationperformance of propeller was predicted to verify the feasibility of numerical method in thispaper. Wake field behind ship and unsteady interaction between ship and propeller werecomputed to study the interaction performance and the pressure distribution on ship surface.Finally, based on the interaction model, numerical simulation of cavitating turbulent flow ofpropeller behind ship hull was studied to analyze cavitation coverage areas, thrust coefficientand efficiency of propeller with different cavitation number.